Digital Communication 21EC51
Module 1`
Digital Modulation Techniques: Phase shift Keying techniques using coherent detection: generation,
detection and error probabilities of BPSK and QPSK, M–ary PSK, M–ary QAM. Frequency shift keying techniques using Coherent detection: BFSK generation, detection and error probability. Non coherent
orthogonal modulation techniques: BFSK, DPSK Symbol representation, Block diagrams treatment of Transmitter and Receiver, Probability of error (without derivation of probability of error equation).
Module 2
Signalling Communication through Band Limited AWGN Channels: Signalling over AWGN Channels- Introduction, Geometric representation of signals, Gram- Schmidt Orthogonalization procedure, Conversion of the continuous AWGN channel into a vector channel (without statistical characterization), Optimum receivers using coherent detection: ML Decoding,
Correlation receiver, matched filter receiver. Signal design for Band limited Channels: Design of band limited signals for zero lSI-The Nyquist Criterion (statement only), Design of band limited signals with controlled lSI-Partial Response signals, Probability of error for detection of Digital PAM: Symbol-by-Symbol detection of data with controlled lSI.
Module 3
Principles of Spread Spectrum: Spread Spectrum Communication Systems: Model of a Spread Spectrum
Digital Communication System, Direct Sequence Spread Spectrum Systems, Effect of De-spreading on a narrowband Interference, Probability of error (statement only), Some applications of DS Spread
Spectrum Signals, Generation of PN Sequences, Frequency Hopped Spread Spectrum, CDMA based on IS-
95.
Module 4
Introduction to Information Theory: Measure of information, Average information content of symbols in long independent sequences.
Source Coding: Encoding of the Source Output, Shannon’s Encoding Algorithm, Shannon-Fano Encoding Algorithm, Huffman coding. Error Control Coding: Introduction, Examples of Error control coding, methods of Controlling Errors,
Types of Errors, types of Codes.
Module 5
Linear Block Codes: Matrix description of Linear Block Codes, Error Detection & Correction capabilities of Linear Block Codes, Single error correction Hamming code, Table lookup Decoding using Standard
Array. Convolution codes: Convolution Encoder, Time domain approach, Transform domain approach, Code Tree, Trellis and State Diagram.